Catalytic Growth of Graphitic Carbon-Coated Silicon as High-Performance Anodes for Lithium Storage

Although silicon is considered as one of the most promising anode materials in next-generation lithium-ion batteries, large volumetric expansion during cycling hampers its practical application. The fabrication of silicon/carbon composites is an effective way to improve electrical conductivity and inhibit electroactive material delaminating from the current collector. Herein, a graphitic carbon-coated porous silicon nanospheres (p-SiNSs@C) composite is prepared through a chemical vapor deposition (CVD) technique by using the magnesiothermic reduction by-product MgO as a template and catalyst. With the template of in situ generation of MgO, the p-SiNSs@C material is obtained in a very short time. Due to the graphitic carbon shell and porous structure inside the silicon nanospheres, the obtained p-SiNSs@C, with 8 min carbon growing time (p-SiNSs@C-2), deliver a high initial reversible capacity of 2220 mAh g(-1) at 0.1 A g(-1) and respectable rate capability. Furthermore, the p-SiNSs@C-2//LiCoO2 Li-ion full cell displays a high energy density of approximate to 409 Wh kg(-1) and good cycling performance. The high performance of the p-SiNSs@C-2 composite can be attributed to the synergistic effect of nanoscale-sized Si, porous structure, and stable carbon shell.